Pathogens in food cause millions of illnesses every year. Certain vegetable oils are very effective in fighting such pathogenic bacteria and fungi in food. Even though olive oil is often viewed as particularly healthy, there are other oils that are much more effective against pathogens in food.
A recent study involving experts from the University of South Africa evaluated how effective various vegetable oils are against common pathogens that cause foodborne illnesses. The results were published in the English-language journal “Microbiological Research”.
How do foodborne illnesses occur?
Foodborne illnesses arise from consuming foods that contain infectious pathogens or toxins. According to the Robert Koch Institute (RKI), there are many different pathogens and toxins that can cause food-borne illnesses.
If the toxins and pathogens enter the body via the digestive tract, this can result, for example, in nausea and vomiting, diarrhea and cramping abdominal pain.
Such illnesses usually only have mild effects, but it is also possible that they can be serious or even fatal. In addition, the pathogens of food-borne illnesses can often be transmitted from person to person, which significantly increases the risk of further spread.
In recent years, the Robert Koch Institute has repeatedly been notified of more than 1,000 outbreaks that were potentially classified as food-related. This indicates how often pathogens lead to foodborne illnesses and how often these then cause a foodborne outbreak.
Natural substances for protection
As more and more people are concerned about the side effects of chemical and synthetic preservatives intended to prevent the emergence of foodborne illness pathogens, there is a high demand for natural substances as an alternative.
Such alternatives would have to have broad antioxidant and antibacterial properties, emphasizes the research team. Vegetable oils contain bioactive compounds that directly target pathogens, making them potential sources of novel antibacterial agents against foodborne illness pathogens.
However, the composition of the oils varies depending on the plant species, subspecies and the method of extraction. In addition, the effectiveness of plant oils on different pathogens also varies, the researchers add.
Which plant oil is particularly effective?
Laboratory tests showed that neem oil is particularly effective against pathogens. The researchers explain that neem oil has over 140 bioactive compounds that help eliminate harmful bacteria and destroy biofilms.
In the study, neem oil showed significant antibacterial activity against all pathogens tested, with the effect against Staphylococcus aureus and Bacillus cereus being particularly pronounced, the experts added.
Castor oil showed moderate activity overall, but according to the researchers it was particularly effective against E. coli (Gram-negative) and Staphylococcus aureus (Gram-positive) due to its high fatty acid content. The large number of fatty acids in coconut oil, on the other hand, is remarkably effective in the fight against pathogenic bacteria in aquaculture, the team reports.
Olive oil has minimal antibacterial effect
Olive oil, which is often touted as particularly healthy, has only shown a minimal antibacterial effect despite the many phenolic compounds it contains.
The team adds that other plant oils such as tea tree oil, cinnamon bark oil, thyme oil, peppermint oil and oregano oil also have strong antibacterial activity against various pathogens such as Staphylococcus aureus, Escherichia coli, Salmonella spp. and Listeria monocytogenes have shown.
Taken together, however, neem and coconut oil in particular are promising candidates for the development of natural antimicrobial agents and for protection against foodborne illness pathogens due to their rich bioactive components. (as)